There's a reason why people are advised to make sure they have other sources of income beyond Social Security after they retire. If you were an average earner during your working years, that program's benefits will only replace about 40% of your pre-retirement wages.

Most seniors will need a lot more money than that to live comfortably -- especially considering some of the areas where people's expenses often rise during retirement, such as healthcare. Plus, if Congress does not act to address a looming shortfall between the funds generated by payroll taxes and the program's obligations, Social Security benefits may eventually be trimmed back. If that happens, your benefits will amount to an even smaller fraction of the income you brought in during your career.

Now, when it comes to supplementing your Social Security benefits, you have different options. A good one is to build up a nice balance in an Individual Retirement Account or a 401(k) plan -- or both.

A house with a for rent sign on its lawn.

Image source: Getty Images.

But there's another avenue for generating retirement income that's worth looking at -- owning a rental property. If you buy an investment property in the right location, it might generate a nice stream of income for you for years on end.

Boosting your senior income isn't the only benefit of owning a rental property, though. And you may end up appreciating it as an investment for reasons having nothing to do with your finances.

It's a matter of keeping busy

Many seniors struggle once they enter retirement. The reason? They find themselves bored and adrift once they no longer have jobs to go to.

Think about it: If you're accustomed to working 40 hours a week or more, you may find it hard to come up with meaningful or compelling activities to fill all those hours. That's why owning an income property might be a great thing for you in retirement.

Landlords have to take the time to maintain their properties, keep up with tenant requests, and so forth. It's not necessarily a 40-hour-a-week job, but it's a job nonetheless. And at a time in your life when you may be struggling to fill your days, taking on the role of landlord could be a good way to anchor yourself and ensure that your schedule isn't too empty.

Of course, you could also fill those hours with hobbies and volunteer work. But being a landlord comes with the benefit of earning an income, and if you don't have a particularly large nest egg to fall back on, that's important too.

An investment worth considering

Owning an income property isn't without risk. There might be periods when your rental sits vacant. You might end up with a tenant who falls behind, leaving you to deal with late or delinquent rent payments.

The costs of owning your rental property could also rise, eating into your profits. But all told, owning an income property in retirement will give you a way to supplement your Social Security benefits and stay moderately busy too. For those reasons alone, it's worth considering this particular investment.

That said, if you're worried about the time commitment or the financial risk, you may want to find a trusted partner and go in on an income property together. You'll have to share the profits, but you'll also share the work and risk.